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| Sunday, 25 September 2005 |
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Junior Observer |  |
| News Business Features Editorial
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When dinosaurs ruled the world... : Fossil revelations
There are many theories as to why the dinosaurs or dinos disappeared. As there were plant eating and meat eating dinosaurs some suggest the meat-eating dinos such as Tyrannosaurus rex may have eaten all the plant-eating ones, and then they too died out eventually without any food to eat. Another theory suggests that a small, furry mammal which lived in that era raided all the dinosaur eggs and ate the young! Then there is the belief that the vegetation changed and the plant-eating dinosaurs starved because their teeth were not suited to the new woody stemmed plants.
Let's check out some interesting information and theories put forward by scientists about these reptiles,some of whom were not only enormous, but also fearsome... The various fossils discovered from around the world suggest that there were different types of dinosaurs. Some were meat-eaters (theropods) and others plant-eaters (sauropods). There were some that could fly too.
Dinosaur bones were first discovered hundreds of years ago, but as no one knew about these animals then, they were thought to be from giants or dragons. However, in 1822, a person named Georges Cuvier suggested they belonged to giant reptiles. Then two years later, William Buckland named the first dinosaur as Megalosaurus (big lizard). A year later fossil hunters, Mary Anning(1799-1847) and Gideon Mantel(1790-1852) named a second dino. It was called Iguanodon. But who first called them dinosaurs? Richard Owen, in 1842. The word 'dinosaurs' means terrible lizards. Dinosaur fossils (animal and plant remains that have been preserved in rocks), were discovered from various parts of the world. In America alone, over 130 new kinds of dinosaur fossils were discovered by Edward Cope and Othniel Marsh. Today many more fossils have been found bringing new light into these animals that lived long, long ago. Dinosaurs were the biggest land animals that have ever lived on Earth. Of the various types, the largest dinosaurs were the plant-eating sauropods. There were several kinds and they all had huge bodies, long necks and small heads. An unusual combination indeed! Would you believe that some were as tall as a four-storey building? A complete skeleton of a Brachiosaurus which was discovered showed that it could raise its head about 13 metres above the ground.
One Brachiosaurus would have weighed as much as ten large elephants! But it does not hold the record as the heaviest dinosaur. Some of the few bones of Supersaurus and Ultrasaurus discovered have revealed that they both outweighed Brachiosaurus. In fact, Ultrasaurus holds the record at almost 30 metres long, 12 metres high and 130 tonnes in weight. That is as heavy as 20 large elephants. Sauropod dinosaurs had the biggest and heaviest bones. Once a thigh bone weighing 450 kilograms had been found by early fossil-hunters. Some sauropod hip bones discovered are bigger than an adult man. The front feet of sauropods such as Brachiosaurus were huge - up to a metre long and big enough to sit on. Fossil experts, known as Palaeontologists, can work out an animal's size, weight and speed from its footprints. Going by fossil discoveries, experts believe that while Ultrasaurus was the heaviest, Seismosaurus was the longest at 39-52 metres. That is, longer than a blue whale - the biggest animal alive today.Even though palaeontologists could find out many facts about dinosaurs from fossils no one knows for sure what colour they were. A few pieces of fossil dinosaur skin have been found, but the colour had faded millions of years ago. Perhaps they had similar colours to the reptiles of today. Fossils and mummified skin have revealed that many dinosaurs had skin covered with lumps and bumps for protection like most of the animals found today with similar skins.
As the crests and heads had to be noticed when sending signals experts believe they may have been coloured and so dinosaurs may have been able to see colour. However these are only assumptions based on animal behaviour of the present day creatures. More on dinosaurs next week. *** Fact file * Experts have divided the dinosaur age into three main parts - the Triassic, Jurassic and Cretaceous periods. Different dinosaurs lived in each of these periods, so some fossils are older than others. * Some dinosaurs, such as Brachiosaurus, have been found in North America, Africa and Europe. The famous Triceratops and Tyrannosaurus have been found only in North America. * The biggest South American meat-eater found so far is Piatnitzkysaurus. * Hundreds of fossil dinosaurs including Diplodocus, Deinonychus and Stegosaurus have been found in North America. In Europe too hundreds more including large plant-eaters such as Camptosaurus have been found. * Few dinosaur fossils have been found in Australia but thousands of fossil dino footprints have been uncovered in Queensland. * One of the biggest sites in Africa is Tendaguru in Tanzania. Over 200 tonnes of bones were found there between 1909 and 1912. |
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| Politics | Produced by Lake House |
Many animals we are familiar with in our modern world today are
threatened with extinction. If we do not take action to protect such
endangered species, soon they will vanish from the face of the Earth, like
the highly successful species of reptiles that once ruled our world... Of
course, the dinosaurs who walked this Earth for millions and millions of
years did not die out as a result of man's actions like the hundreds of
species under threat of dying out today because of man... 
However, the most widely accepted theory today is that a giant
meteorite which hit the Earth, sending up vast clouds of dust, may have
blocked the sun rays or insulated the Earth so effectively, making it too
cold for life to survive. No matter what happened to wipe them out
millions of years ago, today, dinosaurs continue to fascinate man, and
fuel his imagination following the discovery of various dinosaur fossils
around the world. 
All dinosaur names given by scientists are in Latin and have two parts
- the genus name (group with common characteristics) and the species name.
They are written in italics and the genus name has a capital letter, for
example, Tyrannosaurus rex. Similar species of dinos are put in the same
genus, which is the name usually used. 
As some reptiles in existence today are very colourful, scientists and
fossil experts think dinosaurs too may have been brightly coloured. No one
even knows if dinosaurs could see colour. What is known is that some
dinosaurs which are called hardrosaurs had crests, frills and inflatable
air sacs on their heads which they may have used to send signals, like
some animals of today. 
